METHOD
Mix together the pork, prawns, spring onions, garlic, ginger, oyster sauce and water chestnuts.
Peel off a wonton wrapper and, wiht a pastry brush, lightly brush around teh outside with cold water.
Place 1 tsp of the mixture in the centre and scrunch up into a pouch, squeezing to seal. Do not overfill.
Repeat until you have used all the mixture.
These can be chilled for up to an hour on a tray lined with baking parchment.
For the sauce, mix together the soy sauce, sherry and ginger in a small bowl.
To steam, bring a large pan of water to the boil. Line a bamboo or metal steaming basket with lettuce leaves or baking parchment.
Arrnage half the pouches (or as many as will fit) in the basket without them touching each other. Cover and steam for five minutes.
Using tongs, remove to a warmed plate and steam the rest of them (check the water level in the pan).
Serve, sprinkled with spring onion or sesame seeds, with the dipping sauce.

Variations:
You could use minced turkey instead of pork.
You can make them into half moon shapes instead of pouches.